1 // SPDX-License-Identifier: GPL-1.0+
2 /*
3 * bus driver for ccw devices
4 *
5 * Copyright IBM Corp. 2002, 2008
6 * Author(s): Arnd Bergmann (arndb@de.ibm.com)
7 * Cornelia Huck (cornelia.huck@de.ibm.com)
8 * Martin Schwidefsky (schwidefsky@de.ibm.com)
9 */
10
11 #define KMSG_COMPONENT "cio"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13
14 #include <linux/export.h>
15 #include <linux/init.h>
16 #include <linux/spinlock.h>
17 #include <linux/errno.h>
18 #include <linux/err.h>
19 #include <linux/slab.h>
20 #include <linux/list.h>
21 #include <linux/device.h>
22 #include <linux/workqueue.h>
23 #include <linux/delay.h>
24 #include <linux/timer.h>
25 #include <linux/kernel_stat.h>
26 #include <linux/sched/signal.h>
27 #include <linux/dma-mapping.h>
28
29 #include <asm/ccwdev.h>
30 #include <asm/cio.h>
31 #include <asm/param.h> /* HZ */
32 #include <asm/cmb.h>
33 #include <asm/isc.h>
34
35 #include "chp.h"
36 #include "cio.h"
37 #include "cio_debug.h"
38 #include "css.h"
39 #include "device.h"
40 #include "ioasm.h"
41 #include "io_sch.h"
42 #include "blacklist.h"
43 #include "chsc.h"
44
45 static struct timer_list recovery_timer;
46 static DEFINE_SPINLOCK(recovery_lock);
47 static int recovery_phase;
48 static const unsigned long recovery_delay[] = { 3, 30, 300 };
49
50 static atomic_t ccw_device_init_count = ATOMIC_INIT(0);
51 static DECLARE_WAIT_QUEUE_HEAD(ccw_device_init_wq);
52 static struct bus_type ccw_bus_type;
53
54 /******************* bus type handling ***********************/
55
56 /* The Linux driver model distinguishes between a bus type and
57 * the bus itself. Of course we only have one channel
58 * subsystem driver and one channel system per machine, but
59 * we still use the abstraction. T.R. says it's a good idea. */
60 static int
ccw_bus_match(struct device * dev,struct device_driver * drv)61 ccw_bus_match (struct device * dev, struct device_driver * drv)
62 {
63 struct ccw_device *cdev = to_ccwdev(dev);
64 struct ccw_driver *cdrv = to_ccwdrv(drv);
65 const struct ccw_device_id *ids = cdrv->ids, *found;
66
67 if (!ids)
68 return 0;
69
70 found = ccw_device_id_match(ids, &cdev->id);
71 if (!found)
72 return 0;
73
74 cdev->id.driver_info = found->driver_info;
75
76 return 1;
77 }
78
79 /* Store modalias string delimited by prefix/suffix string into buffer with
80 * specified size. Return length of resulting string (excluding trailing '\0')
81 * even if string doesn't fit buffer (snprintf semantics). */
snprint_alias(char * buf,size_t size,struct ccw_device_id * id,const char * suffix)82 static int snprint_alias(char *buf, size_t size,
83 struct ccw_device_id *id, const char *suffix)
84 {
85 int len;
86
87 len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
88 if (len > size)
89 return len;
90 buf += len;
91 size -= len;
92
93 if (id->dev_type != 0)
94 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
95 id->dev_model, suffix);
96 else
97 len += snprintf(buf, size, "dtdm%s", suffix);
98
99 return len;
100 }
101
102 /* Set up environment variables for ccw device uevent. Return 0 on success,
103 * non-zero otherwise. */
ccw_uevent(struct device * dev,struct kobj_uevent_env * env)104 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
105 {
106 struct ccw_device *cdev = to_ccwdev(dev);
107 struct ccw_device_id *id = &(cdev->id);
108 int ret;
109 char modalias_buf[30];
110
111 /* CU_TYPE= */
112 ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
113 if (ret)
114 return ret;
115
116 /* CU_MODEL= */
117 ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
118 if (ret)
119 return ret;
120
121 /* The next two can be zero, that's ok for us */
122 /* DEV_TYPE= */
123 ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
124 if (ret)
125 return ret;
126
127 /* DEV_MODEL= */
128 ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
129 if (ret)
130 return ret;
131
132 /* MODALIAS= */
133 snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
134 ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
135 return ret;
136 }
137
138 static void io_subchannel_irq(struct subchannel *);
139 static int io_subchannel_probe(struct subchannel *);
140 static void io_subchannel_remove(struct subchannel *);
141 static void io_subchannel_shutdown(struct subchannel *);
142 static int io_subchannel_sch_event(struct subchannel *, int);
143 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
144 int);
145 static void recovery_func(struct timer_list *unused);
146
147 static struct css_device_id io_subchannel_ids[] = {
148 { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
149 { /* end of list */ },
150 };
151
io_subchannel_settle(void)152 static int io_subchannel_settle(void)
153 {
154 int ret;
155
156 ret = wait_event_interruptible(ccw_device_init_wq,
157 atomic_read(&ccw_device_init_count) == 0);
158 if (ret)
159 return -EINTR;
160 flush_workqueue(cio_work_q);
161 return 0;
162 }
163
164 static struct css_driver io_subchannel_driver = {
165 .drv = {
166 .owner = THIS_MODULE,
167 .name = "io_subchannel",
168 },
169 .subchannel_type = io_subchannel_ids,
170 .irq = io_subchannel_irq,
171 .sch_event = io_subchannel_sch_event,
172 .chp_event = io_subchannel_chp_event,
173 .probe = io_subchannel_probe,
174 .remove = io_subchannel_remove,
175 .shutdown = io_subchannel_shutdown,
176 .settle = io_subchannel_settle,
177 };
178
io_subchannel_init(void)179 int __init io_subchannel_init(void)
180 {
181 int ret;
182
183 timer_setup(&recovery_timer, recovery_func, 0);
184 ret = bus_register(&ccw_bus_type);
185 if (ret)
186 return ret;
187 ret = css_driver_register(&io_subchannel_driver);
188 if (ret)
189 bus_unregister(&ccw_bus_type);
190
191 return ret;
192 }
193
194
195 /************************ device handling **************************/
196
197 static ssize_t
devtype_show(struct device * dev,struct device_attribute * attr,char * buf)198 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
199 {
200 struct ccw_device *cdev = to_ccwdev(dev);
201 struct ccw_device_id *id = &(cdev->id);
202
203 if (id->dev_type != 0)
204 return sprintf(buf, "%04x/%02x\n",
205 id->dev_type, id->dev_model);
206 else
207 return sprintf(buf, "n/a\n");
208 }
209
210 static ssize_t
cutype_show(struct device * dev,struct device_attribute * attr,char * buf)211 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
212 {
213 struct ccw_device *cdev = to_ccwdev(dev);
214 struct ccw_device_id *id = &(cdev->id);
215
216 return sprintf(buf, "%04x/%02x\n",
217 id->cu_type, id->cu_model);
218 }
219
220 static ssize_t
modalias_show(struct device * dev,struct device_attribute * attr,char * buf)221 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
222 {
223 struct ccw_device *cdev = to_ccwdev(dev);
224 struct ccw_device_id *id = &(cdev->id);
225 int len;
226
227 len = snprint_alias(buf, PAGE_SIZE, id, "\n");
228
229 return len > PAGE_SIZE ? PAGE_SIZE : len;
230 }
231
232 static ssize_t
online_show(struct device * dev,struct device_attribute * attr,char * buf)233 online_show (struct device *dev, struct device_attribute *attr, char *buf)
234 {
235 struct ccw_device *cdev = to_ccwdev(dev);
236
237 return sprintf(buf, cdev->online ? "1\n" : "0\n");
238 }
239
ccw_device_is_orphan(struct ccw_device * cdev)240 int ccw_device_is_orphan(struct ccw_device *cdev)
241 {
242 return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
243 }
244
ccw_device_unregister(struct ccw_device * cdev)245 static void ccw_device_unregister(struct ccw_device *cdev)
246 {
247 if (device_is_registered(&cdev->dev)) {
248 /* Undo device_add(). */
249 device_del(&cdev->dev);
250 }
251 if (cdev->private->flags.initialized) {
252 cdev->private->flags.initialized = 0;
253 /* Release reference from device_initialize(). */
254 put_device(&cdev->dev);
255 }
256 }
257
258 static void io_subchannel_quiesce(struct subchannel *);
259
260 /**
261 * ccw_device_set_offline() - disable a ccw device for I/O
262 * @cdev: target ccw device
263 *
264 * This function calls the driver's set_offline() function for @cdev, if
265 * given, and then disables @cdev.
266 * Returns:
267 * %0 on success and a negative error value on failure.
268 * Context:
269 * enabled, ccw device lock not held
270 */
ccw_device_set_offline(struct ccw_device * cdev)271 int ccw_device_set_offline(struct ccw_device *cdev)
272 {
273 struct subchannel *sch;
274 int ret, state;
275
276 if (!cdev)
277 return -ENODEV;
278 if (!cdev->online || !cdev->drv)
279 return -EINVAL;
280
281 if (cdev->drv->set_offline) {
282 ret = cdev->drv->set_offline(cdev);
283 if (ret != 0)
284 return ret;
285 }
286 spin_lock_irq(cdev->ccwlock);
287 sch = to_subchannel(cdev->dev.parent);
288 cdev->online = 0;
289 /* Wait until a final state or DISCONNECTED is reached */
290 while (!dev_fsm_final_state(cdev) &&
291 cdev->private->state != DEV_STATE_DISCONNECTED) {
292 spin_unlock_irq(cdev->ccwlock);
293 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
294 cdev->private->state == DEV_STATE_DISCONNECTED));
295 spin_lock_irq(cdev->ccwlock);
296 }
297 do {
298 ret = ccw_device_offline(cdev);
299 if (!ret)
300 break;
301 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
302 "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
303 cdev->private->dev_id.devno);
304 if (ret != -EBUSY)
305 goto error;
306 state = cdev->private->state;
307 spin_unlock_irq(cdev->ccwlock);
308 io_subchannel_quiesce(sch);
309 spin_lock_irq(cdev->ccwlock);
310 cdev->private->state = state;
311 } while (ret == -EBUSY);
312 spin_unlock_irq(cdev->ccwlock);
313 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
314 cdev->private->state == DEV_STATE_DISCONNECTED));
315 /* Inform the user if set offline failed. */
316 if (cdev->private->state == DEV_STATE_BOXED) {
317 pr_warn("%s: The device entered boxed state while being set offline\n",
318 dev_name(&cdev->dev));
319 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
320 pr_warn("%s: The device stopped operating while being set offline\n",
321 dev_name(&cdev->dev));
322 }
323 /* Give up reference from ccw_device_set_online(). */
324 put_device(&cdev->dev);
325 return 0;
326
327 error:
328 cdev->private->state = DEV_STATE_OFFLINE;
329 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
330 spin_unlock_irq(cdev->ccwlock);
331 /* Give up reference from ccw_device_set_online(). */
332 put_device(&cdev->dev);
333 return -ENODEV;
334 }
335
336 /**
337 * ccw_device_set_online() - enable a ccw device for I/O
338 * @cdev: target ccw device
339 *
340 * This function first enables @cdev and then calls the driver's set_online()
341 * function for @cdev, if given. If set_online() returns an error, @cdev is
342 * disabled again.
343 * Returns:
344 * %0 on success and a negative error value on failure.
345 * Context:
346 * enabled, ccw device lock not held
347 */
ccw_device_set_online(struct ccw_device * cdev)348 int ccw_device_set_online(struct ccw_device *cdev)
349 {
350 int ret;
351 int ret2;
352
353 if (!cdev)
354 return -ENODEV;
355 if (cdev->online || !cdev->drv)
356 return -EINVAL;
357 /* Hold on to an extra reference while device is online. */
358 if (!get_device(&cdev->dev))
359 return -ENODEV;
360
361 spin_lock_irq(cdev->ccwlock);
362 ret = ccw_device_online(cdev);
363 spin_unlock_irq(cdev->ccwlock);
364 if (ret == 0)
365 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
366 else {
367 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
368 "device 0.%x.%04x\n",
369 ret, cdev->private->dev_id.ssid,
370 cdev->private->dev_id.devno);
371 /* Give up online reference since onlining failed. */
372 put_device(&cdev->dev);
373 return ret;
374 }
375 spin_lock_irq(cdev->ccwlock);
376 /* Check if online processing was successful */
377 if ((cdev->private->state != DEV_STATE_ONLINE) &&
378 (cdev->private->state != DEV_STATE_W4SENSE)) {
379 spin_unlock_irq(cdev->ccwlock);
380 /* Inform the user that set online failed. */
381 if (cdev->private->state == DEV_STATE_BOXED) {
382 pr_warn("%s: Setting the device online failed because it is boxed\n",
383 dev_name(&cdev->dev));
384 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
385 pr_warn("%s: Setting the device online failed because it is not operational\n",
386 dev_name(&cdev->dev));
387 }
388 /* Give up online reference since onlining failed. */
389 put_device(&cdev->dev);
390 return -ENODEV;
391 }
392 spin_unlock_irq(cdev->ccwlock);
393 if (cdev->drv->set_online)
394 ret = cdev->drv->set_online(cdev);
395 if (ret)
396 goto rollback;
397
398 spin_lock_irq(cdev->ccwlock);
399 cdev->online = 1;
400 spin_unlock_irq(cdev->ccwlock);
401 return 0;
402
403 rollback:
404 spin_lock_irq(cdev->ccwlock);
405 /* Wait until a final state or DISCONNECTED is reached */
406 while (!dev_fsm_final_state(cdev) &&
407 cdev->private->state != DEV_STATE_DISCONNECTED) {
408 spin_unlock_irq(cdev->ccwlock);
409 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
410 cdev->private->state == DEV_STATE_DISCONNECTED));
411 spin_lock_irq(cdev->ccwlock);
412 }
413 ret2 = ccw_device_offline(cdev);
414 if (ret2)
415 goto error;
416 spin_unlock_irq(cdev->ccwlock);
417 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
418 cdev->private->state == DEV_STATE_DISCONNECTED));
419 /* Give up online reference since onlining failed. */
420 put_device(&cdev->dev);
421 return ret;
422
423 error:
424 CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
425 "device 0.%x.%04x\n",
426 ret2, cdev->private->dev_id.ssid,
427 cdev->private->dev_id.devno);
428 cdev->private->state = DEV_STATE_OFFLINE;
429 spin_unlock_irq(cdev->ccwlock);
430 /* Give up online reference since onlining failed. */
431 put_device(&cdev->dev);
432 return ret;
433 }
434
online_store_handle_offline(struct ccw_device * cdev)435 static int online_store_handle_offline(struct ccw_device *cdev)
436 {
437 if (cdev->private->state == DEV_STATE_DISCONNECTED) {
438 spin_lock_irq(cdev->ccwlock);
439 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
440 spin_unlock_irq(cdev->ccwlock);
441 return 0;
442 }
443 if (cdev->drv && cdev->drv->set_offline)
444 return ccw_device_set_offline(cdev);
445 return -EINVAL;
446 }
447
online_store_recog_and_online(struct ccw_device * cdev)448 static int online_store_recog_and_online(struct ccw_device *cdev)
449 {
450 /* Do device recognition, if needed. */
451 if (cdev->private->state == DEV_STATE_BOXED) {
452 spin_lock_irq(cdev->ccwlock);
453 ccw_device_recognition(cdev);
454 spin_unlock_irq(cdev->ccwlock);
455 wait_event(cdev->private->wait_q,
456 cdev->private->flags.recog_done);
457 if (cdev->private->state != DEV_STATE_OFFLINE)
458 /* recognition failed */
459 return -EAGAIN;
460 }
461 if (cdev->drv && cdev->drv->set_online)
462 return ccw_device_set_online(cdev);
463 return -EINVAL;
464 }
465
online_store_handle_online(struct ccw_device * cdev,int force)466 static int online_store_handle_online(struct ccw_device *cdev, int force)
467 {
468 int ret;
469
470 ret = online_store_recog_and_online(cdev);
471 if (ret && !force)
472 return ret;
473 if (force && cdev->private->state == DEV_STATE_BOXED) {
474 ret = ccw_device_stlck(cdev);
475 if (ret)
476 return ret;
477 if (cdev->id.cu_type == 0)
478 cdev->private->state = DEV_STATE_NOT_OPER;
479 ret = online_store_recog_and_online(cdev);
480 if (ret)
481 return ret;
482 }
483 return 0;
484 }
485
online_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)486 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
487 const char *buf, size_t count)
488 {
489 struct ccw_device *cdev = to_ccwdev(dev);
490 int force, ret;
491 unsigned long i;
492
493 /* Prevent conflict between multiple on-/offline processing requests. */
494 if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
495 return -EAGAIN;
496 /* Prevent conflict between internal I/Os and on-/offline processing. */
497 if (!dev_fsm_final_state(cdev) &&
498 cdev->private->state != DEV_STATE_DISCONNECTED) {
499 ret = -EAGAIN;
500 goto out;
501 }
502 /* Prevent conflict between pending work and on-/offline processing.*/
503 if (work_pending(&cdev->private->todo_work)) {
504 ret = -EAGAIN;
505 goto out;
506 }
507 if (!strncmp(buf, "force\n", count)) {
508 force = 1;
509 i = 1;
510 ret = 0;
511 } else {
512 force = 0;
513 ret = kstrtoul(buf, 16, &i);
514 }
515 if (ret)
516 goto out;
517
518 device_lock(dev);
519 switch (i) {
520 case 0:
521 ret = online_store_handle_offline(cdev);
522 break;
523 case 1:
524 ret = online_store_handle_online(cdev, force);
525 break;
526 default:
527 ret = -EINVAL;
528 }
529 device_unlock(dev);
530
531 out:
532 atomic_set(&cdev->private->onoff, 0);
533 return (ret < 0) ? ret : count;
534 }
535
536 static ssize_t
available_show(struct device * dev,struct device_attribute * attr,char * buf)537 available_show (struct device *dev, struct device_attribute *attr, char *buf)
538 {
539 struct ccw_device *cdev = to_ccwdev(dev);
540 struct subchannel *sch;
541
542 if (ccw_device_is_orphan(cdev))
543 return sprintf(buf, "no device\n");
544 switch (cdev->private->state) {
545 case DEV_STATE_BOXED:
546 return sprintf(buf, "boxed\n");
547 case DEV_STATE_DISCONNECTED:
548 case DEV_STATE_DISCONNECTED_SENSE_ID:
549 case DEV_STATE_NOT_OPER:
550 sch = to_subchannel(dev->parent);
551 if (!sch->lpm)
552 return sprintf(buf, "no path\n");
553 else
554 return sprintf(buf, "no device\n");
555 default:
556 /* All other states considered fine. */
557 return sprintf(buf, "good\n");
558 }
559 }
560
561 static ssize_t
initiate_logging(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)562 initiate_logging(struct device *dev, struct device_attribute *attr,
563 const char *buf, size_t count)
564 {
565 struct subchannel *sch = to_subchannel(dev);
566 int rc;
567
568 rc = chsc_siosl(sch->schid);
569 if (rc < 0) {
570 pr_warn("Logging for subchannel 0.%x.%04x failed with errno=%d\n",
571 sch->schid.ssid, sch->schid.sch_no, rc);
572 return rc;
573 }
574 pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
575 sch->schid.ssid, sch->schid.sch_no);
576 return count;
577 }
578
vpm_show(struct device * dev,struct device_attribute * attr,char * buf)579 static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
580 char *buf)
581 {
582 struct subchannel *sch = to_subchannel(dev);
583
584 return sprintf(buf, "%02x\n", sch->vpm);
585 }
586
587 static DEVICE_ATTR_RO(devtype);
588 static DEVICE_ATTR_RO(cutype);
589 static DEVICE_ATTR_RO(modalias);
590 static DEVICE_ATTR_RW(online);
591 static DEVICE_ATTR(availability, 0444, available_show, NULL);
592 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
593 static DEVICE_ATTR_RO(vpm);
594
595 static struct attribute *io_subchannel_attrs[] = {
596 &dev_attr_logging.attr,
597 &dev_attr_vpm.attr,
598 NULL,
599 };
600
601 static const struct attribute_group io_subchannel_attr_group = {
602 .attrs = io_subchannel_attrs,
603 };
604
605 static struct attribute * ccwdev_attrs[] = {
606 &dev_attr_devtype.attr,
607 &dev_attr_cutype.attr,
608 &dev_attr_modalias.attr,
609 &dev_attr_online.attr,
610 &dev_attr_cmb_enable.attr,
611 &dev_attr_availability.attr,
612 NULL,
613 };
614
615 static const struct attribute_group ccwdev_attr_group = {
616 .attrs = ccwdev_attrs,
617 };
618
619 static const struct attribute_group *ccwdev_attr_groups[] = {
620 &ccwdev_attr_group,
621 NULL,
622 };
623
match_dev_id(struct device * dev,const void * data)624 static int match_dev_id(struct device *dev, const void *data)
625 {
626 struct ccw_device *cdev = to_ccwdev(dev);
627 struct ccw_dev_id *dev_id = (void *)data;
628
629 return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
630 }
631
632 /**
633 * get_ccwdev_by_dev_id() - obtain device from a ccw device id
634 * @dev_id: id of the device to be searched
635 *
636 * This function searches all devices attached to the ccw bus for a device
637 * matching @dev_id.
638 * Returns:
639 * If a device is found its reference count is increased and returned;
640 * else %NULL is returned.
641 */
get_ccwdev_by_dev_id(struct ccw_dev_id * dev_id)642 struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
643 {
644 struct device *dev;
645
646 dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
647
648 return dev ? to_ccwdev(dev) : NULL;
649 }
650 EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
651
ccw_device_do_unbind_bind(struct ccw_device * cdev)652 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
653 {
654 int ret;
655
656 if (device_is_registered(&cdev->dev)) {
657 device_release_driver(&cdev->dev);
658 ret = device_attach(&cdev->dev);
659 WARN_ON(ret == -ENODEV);
660 }
661 }
662
663 static void
ccw_device_release(struct device * dev)664 ccw_device_release(struct device *dev)
665 {
666 struct ccw_device *cdev;
667
668 cdev = to_ccwdev(dev);
669 cio_gp_dma_free(cdev->private->dma_pool, cdev->private->dma_area,
670 sizeof(*cdev->private->dma_area));
671 cio_gp_dma_destroy(cdev->private->dma_pool, &cdev->dev);
672 /* Release reference of parent subchannel. */
673 put_device(cdev->dev.parent);
674 kfree(cdev->private);
675 kfree(cdev);
676 }
677
io_subchannel_allocate_dev(struct subchannel * sch)678 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
679 {
680 struct ccw_device *cdev;
681 struct gen_pool *dma_pool;
682 int ret;
683
684 cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
685 if (!cdev) {
686 ret = -ENOMEM;
687 goto err_cdev;
688 }
689 cdev->private = kzalloc(sizeof(struct ccw_device_private),
690 GFP_KERNEL | GFP_DMA);
691 if (!cdev->private) {
692 ret = -ENOMEM;
693 goto err_priv;
694 }
695
696 cdev->dev.dma_mask = sch->dev.dma_mask;
697 ret = dma_set_coherent_mask(&cdev->dev, sch->dev.coherent_dma_mask);
698 if (ret)
699 goto err_coherent_mask;
700
701 dma_pool = cio_gp_dma_create(&cdev->dev, 1);
702 if (!dma_pool) {
703 ret = -ENOMEM;
704 goto err_dma_pool;
705 }
706 cdev->private->dma_pool = dma_pool;
707 cdev->private->dma_area = cio_gp_dma_zalloc(dma_pool, &cdev->dev,
708 sizeof(*cdev->private->dma_area));
709 if (!cdev->private->dma_area) {
710 ret = -ENOMEM;
711 goto err_dma_area;
712 }
713 return cdev;
714 err_dma_area:
715 cio_gp_dma_destroy(dma_pool, &cdev->dev);
716 err_dma_pool:
717 err_coherent_mask:
718 kfree(cdev->private);
719 err_priv:
720 kfree(cdev);
721 err_cdev:
722 return ERR_PTR(ret);
723 }
724
725 static void ccw_device_todo(struct work_struct *work);
726
io_subchannel_initialize_dev(struct subchannel * sch,struct ccw_device * cdev)727 static int io_subchannel_initialize_dev(struct subchannel *sch,
728 struct ccw_device *cdev)
729 {
730 struct ccw_device_private *priv = cdev->private;
731 int ret;
732
733 priv->cdev = cdev;
734 priv->int_class = IRQIO_CIO;
735 priv->state = DEV_STATE_NOT_OPER;
736 priv->dev_id.devno = sch->schib.pmcw.dev;
737 priv->dev_id.ssid = sch->schid.ssid;
738
739 INIT_WORK(&priv->todo_work, ccw_device_todo);
740 INIT_LIST_HEAD(&priv->cmb_list);
741 init_waitqueue_head(&priv->wait_q);
742 timer_setup(&priv->timer, ccw_device_timeout, 0);
743
744 atomic_set(&priv->onoff, 0);
745 cdev->ccwlock = sch->lock;
746 cdev->dev.parent = &sch->dev;
747 cdev->dev.release = ccw_device_release;
748 cdev->dev.bus = &ccw_bus_type;
749 cdev->dev.groups = ccwdev_attr_groups;
750 /* Do first half of device_register. */
751 device_initialize(&cdev->dev);
752 ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
753 cdev->private->dev_id.devno);
754 if (ret)
755 goto out_put;
756 if (!get_device(&sch->dev)) {
757 ret = -ENODEV;
758 goto out_put;
759 }
760 priv->flags.initialized = 1;
761 spin_lock_irq(sch->lock);
762 sch_set_cdev(sch, cdev);
763 spin_unlock_irq(sch->lock);
764 return 0;
765
766 out_put:
767 /* Release reference from device_initialize(). */
768 put_device(&cdev->dev);
769 return ret;
770 }
771
io_subchannel_create_ccwdev(struct subchannel * sch)772 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
773 {
774 struct ccw_device *cdev;
775 int ret;
776
777 cdev = io_subchannel_allocate_dev(sch);
778 if (!IS_ERR(cdev)) {
779 ret = io_subchannel_initialize_dev(sch, cdev);
780 if (ret)
781 cdev = ERR_PTR(ret);
782 }
783 return cdev;
784 }
785
786 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
787
sch_create_and_recog_new_device(struct subchannel * sch)788 static void sch_create_and_recog_new_device(struct subchannel *sch)
789 {
790 struct ccw_device *cdev;
791
792 /* Need to allocate a new ccw device. */
793 cdev = io_subchannel_create_ccwdev(sch);
794 if (IS_ERR(cdev)) {
795 /* OK, we did everything we could... */
796 css_sch_device_unregister(sch);
797 return;
798 }
799 /* Start recognition for the new ccw device. */
800 io_subchannel_recog(cdev, sch);
801 }
802
803 /*
804 * Register recognized device.
805 */
io_subchannel_register(struct ccw_device * cdev)806 static void io_subchannel_register(struct ccw_device *cdev)
807 {
808 struct subchannel *sch;
809 int ret, adjust_init_count = 1;
810 unsigned long flags;
811
812 sch = to_subchannel(cdev->dev.parent);
813 /*
814 * Check if subchannel is still registered. It may have become
815 * unregistered if a machine check hit us after finishing
816 * device recognition but before the register work could be
817 * queued.
818 */
819 if (!device_is_registered(&sch->dev))
820 goto out_err;
821 css_update_ssd_info(sch);
822 /*
823 * io_subchannel_register() will also be called after device
824 * recognition has been done for a boxed device (which will already
825 * be registered). We need to reprobe since we may now have sense id
826 * information.
827 */
828 if (device_is_registered(&cdev->dev)) {
829 if (!cdev->drv) {
830 ret = device_reprobe(&cdev->dev);
831 if (ret)
832 /* We can't do much here. */
833 CIO_MSG_EVENT(0, "device_reprobe() returned"
834 " %d for 0.%x.%04x\n", ret,
835 cdev->private->dev_id.ssid,
836 cdev->private->dev_id.devno);
837 }
838 adjust_init_count = 0;
839 goto out;
840 }
841 /*
842 * Now we know this subchannel will stay, we can throw
843 * our delayed uevent.
844 */
845 if (dev_get_uevent_suppress(&sch->dev)) {
846 dev_set_uevent_suppress(&sch->dev, 0);
847 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
848 }
849 /* make it known to the system */
850 ret = device_add(&cdev->dev);
851 if (ret) {
852 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
853 cdev->private->dev_id.ssid,
854 cdev->private->dev_id.devno, ret);
855 spin_lock_irqsave(sch->lock, flags);
856 sch_set_cdev(sch, NULL);
857 spin_unlock_irqrestore(sch->lock, flags);
858 /* Release initial device reference. */
859 put_device(&cdev->dev);
860 goto out_err;
861 }
862 out:
863 cdev->private->flags.recog_done = 1;
864 wake_up(&cdev->private->wait_q);
865 out_err:
866 if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
867 wake_up(&ccw_device_init_wq);
868 }
869
870 /*
871 * subchannel recognition done. Called from the state machine.
872 */
873 void
io_subchannel_recog_done(struct ccw_device * cdev)874 io_subchannel_recog_done(struct ccw_device *cdev)
875 {
876 if (css_init_done == 0) {
877 cdev->private->flags.recog_done = 1;
878 return;
879 }
880 switch (cdev->private->state) {
881 case DEV_STATE_BOXED:
882 /* Device did not respond in time. */
883 case DEV_STATE_NOT_OPER:
884 cdev->private->flags.recog_done = 1;
885 /* Remove device found not operational. */
886 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
887 if (atomic_dec_and_test(&ccw_device_init_count))
888 wake_up(&ccw_device_init_wq);
889 break;
890 case DEV_STATE_OFFLINE:
891 /*
892 * We can't register the device in interrupt context so
893 * we schedule a work item.
894 */
895 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
896 break;
897 }
898 }
899
io_subchannel_recog(struct ccw_device * cdev,struct subchannel * sch)900 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
901 {
902 /* Increase counter of devices currently in recognition. */
903 atomic_inc(&ccw_device_init_count);
904
905 /* Start async. device sensing. */
906 spin_lock_irq(sch->lock);
907 ccw_device_recognition(cdev);
908 spin_unlock_irq(sch->lock);
909 }
910
ccw_device_move_to_sch(struct ccw_device * cdev,struct subchannel * sch)911 static int ccw_device_move_to_sch(struct ccw_device *cdev,
912 struct subchannel *sch)
913 {
914 struct subchannel *old_sch;
915 int rc, old_enabled = 0;
916
917 old_sch = to_subchannel(cdev->dev.parent);
918 /* Obtain child reference for new parent. */
919 if (!get_device(&sch->dev))
920 return -ENODEV;
921
922 if (!sch_is_pseudo_sch(old_sch)) {
923 spin_lock_irq(old_sch->lock);
924 old_enabled = old_sch->schib.pmcw.ena;
925 rc = 0;
926 if (old_enabled)
927 rc = cio_disable_subchannel(old_sch);
928 spin_unlock_irq(old_sch->lock);
929 if (rc == -EBUSY) {
930 /* Release child reference for new parent. */
931 put_device(&sch->dev);
932 return rc;
933 }
934 }
935
936 mutex_lock(&sch->reg_mutex);
937 rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
938 mutex_unlock(&sch->reg_mutex);
939 if (rc) {
940 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
941 cdev->private->dev_id.ssid,
942 cdev->private->dev_id.devno, sch->schid.ssid,
943 sch->schib.pmcw.dev, rc);
944 if (old_enabled) {
945 /* Try to reenable the old subchannel. */
946 spin_lock_irq(old_sch->lock);
947 cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
948 spin_unlock_irq(old_sch->lock);
949 }
950 /* Release child reference for new parent. */
951 put_device(&sch->dev);
952 return rc;
953 }
954 /* Clean up old subchannel. */
955 if (!sch_is_pseudo_sch(old_sch)) {
956 spin_lock_irq(old_sch->lock);
957 sch_set_cdev(old_sch, NULL);
958 spin_unlock_irq(old_sch->lock);
959 css_schedule_eval(old_sch->schid);
960 }
961 /* Release child reference for old parent. */
962 put_device(&old_sch->dev);
963 /* Initialize new subchannel. */
964 spin_lock_irq(sch->lock);
965 cdev->ccwlock = sch->lock;
966 if (!sch_is_pseudo_sch(sch))
967 sch_set_cdev(sch, cdev);
968 spin_unlock_irq(sch->lock);
969 if (!sch_is_pseudo_sch(sch))
970 css_update_ssd_info(sch);
971 return 0;
972 }
973
ccw_device_move_to_orph(struct ccw_device * cdev)974 static int ccw_device_move_to_orph(struct ccw_device *cdev)
975 {
976 struct subchannel *sch = to_subchannel(cdev->dev.parent);
977 struct channel_subsystem *css = to_css(sch->dev.parent);
978
979 return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
980 }
981
io_subchannel_irq(struct subchannel * sch)982 static void io_subchannel_irq(struct subchannel *sch)
983 {
984 struct ccw_device *cdev;
985
986 cdev = sch_get_cdev(sch);
987
988 CIO_TRACE_EVENT(6, "IRQ");
989 CIO_TRACE_EVENT(6, dev_name(&sch->dev));
990 if (cdev)
991 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
992 else
993 inc_irq_stat(IRQIO_CIO);
994 }
995
io_subchannel_init_config(struct subchannel * sch)996 void io_subchannel_init_config(struct subchannel *sch)
997 {
998 memset(&sch->config, 0, sizeof(sch->config));
999 sch->config.csense = 1;
1000 }
1001
io_subchannel_init_fields(struct subchannel * sch)1002 static void io_subchannel_init_fields(struct subchannel *sch)
1003 {
1004 if (cio_is_console(sch->schid))
1005 sch->opm = 0xff;
1006 else
1007 sch->opm = chp_get_sch_opm(sch);
1008 sch->lpm = sch->schib.pmcw.pam & sch->opm;
1009 sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1010
1011 CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1012 " - PIM = %02X, PAM = %02X, POM = %02X\n",
1013 sch->schib.pmcw.dev, sch->schid.ssid,
1014 sch->schid.sch_no, sch->schib.pmcw.pim,
1015 sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1016
1017 io_subchannel_init_config(sch);
1018 }
1019
1020 /*
1021 * Note: We always return 0 so that we bind to the device even on error.
1022 * This is needed so that our remove function is called on unregister.
1023 */
io_subchannel_probe(struct subchannel * sch)1024 static int io_subchannel_probe(struct subchannel *sch)
1025 {
1026 struct io_subchannel_private *io_priv;
1027 struct ccw_device *cdev;
1028 int rc;
1029
1030 if (cio_is_console(sch->schid)) {
1031 rc = sysfs_create_group(&sch->dev.kobj,
1032 &io_subchannel_attr_group);
1033 if (rc)
1034 CIO_MSG_EVENT(0, "Failed to create io subchannel "
1035 "attributes for subchannel "
1036 "0.%x.%04x (rc=%d)\n",
1037 sch->schid.ssid, sch->schid.sch_no, rc);
1038 /*
1039 * The console subchannel already has an associated ccw_device.
1040 * Throw the delayed uevent for the subchannel, register
1041 * the ccw_device and exit.
1042 */
1043 if (dev_get_uevent_suppress(&sch->dev)) {
1044 /* should always be the case for the console */
1045 dev_set_uevent_suppress(&sch->dev, 0);
1046 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1047 }
1048 cdev = sch_get_cdev(sch);
1049 rc = device_add(&cdev->dev);
1050 if (rc) {
1051 /* Release online reference. */
1052 put_device(&cdev->dev);
1053 goto out_schedule;
1054 }
1055 if (atomic_dec_and_test(&ccw_device_init_count))
1056 wake_up(&ccw_device_init_wq);
1057 return 0;
1058 }
1059 io_subchannel_init_fields(sch);
1060 rc = cio_commit_config(sch);
1061 if (rc)
1062 goto out_schedule;
1063 rc = sysfs_create_group(&sch->dev.kobj,
1064 &io_subchannel_attr_group);
1065 if (rc)
1066 goto out_schedule;
1067 /* Allocate I/O subchannel private data. */
1068 io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1069 if (!io_priv)
1070 goto out_schedule;
1071
1072 io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1073 sizeof(*io_priv->dma_area),
1074 &io_priv->dma_area_dma, GFP_KERNEL);
1075 if (!io_priv->dma_area) {
1076 kfree(io_priv);
1077 goto out_schedule;
1078 }
1079
1080 set_io_private(sch, io_priv);
1081 css_schedule_eval(sch->schid);
1082 return 0;
1083
1084 out_schedule:
1085 spin_lock_irq(sch->lock);
1086 css_sched_sch_todo(sch, SCH_TODO_UNREG);
1087 spin_unlock_irq(sch->lock);
1088 return 0;
1089 }
1090
io_subchannel_remove(struct subchannel * sch)1091 static void io_subchannel_remove(struct subchannel *sch)
1092 {
1093 struct io_subchannel_private *io_priv = to_io_private(sch);
1094 struct ccw_device *cdev;
1095
1096 cdev = sch_get_cdev(sch);
1097 if (!cdev)
1098 goto out_free;
1099
1100 ccw_device_unregister(cdev);
1101 spin_lock_irq(sch->lock);
1102 sch_set_cdev(sch, NULL);
1103 set_io_private(sch, NULL);
1104 spin_unlock_irq(sch->lock);
1105 out_free:
1106 dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1107 io_priv->dma_area, io_priv->dma_area_dma);
1108 kfree(io_priv);
1109 sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1110 }
1111
io_subchannel_verify(struct subchannel * sch)1112 static void io_subchannel_verify(struct subchannel *sch)
1113 {
1114 struct ccw_device *cdev;
1115
1116 cdev = sch_get_cdev(sch);
1117 if (cdev)
1118 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1119 else
1120 css_schedule_eval(sch->schid);
1121 }
1122
io_subchannel_terminate_path(struct subchannel * sch,u8 mask)1123 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1124 {
1125 struct ccw_device *cdev;
1126
1127 cdev = sch_get_cdev(sch);
1128 if (!cdev)
1129 return;
1130 if (cio_update_schib(sch))
1131 goto err;
1132 /* Check for I/O on path. */
1133 if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1134 goto out;
1135 if (cdev->private->state == DEV_STATE_ONLINE) {
1136 ccw_device_kill_io(cdev);
1137 goto out;
1138 }
1139 if (cio_clear(sch))
1140 goto err;
1141 out:
1142 /* Trigger path verification. */
1143 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1144 return;
1145
1146 err:
1147 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1148 }
1149
io_subchannel_chp_event(struct subchannel * sch,struct chp_link * link,int event)1150 static int io_subchannel_chp_event(struct subchannel *sch,
1151 struct chp_link *link, int event)
1152 {
1153 struct ccw_device *cdev = sch_get_cdev(sch);
1154 int mask, chpid, valid_bit;
1155 int path_event[8];
1156
1157 mask = chp_ssd_get_mask(&sch->ssd_info, link);
1158 if (!mask)
1159 return 0;
1160 switch (event) {
1161 case CHP_VARY_OFF:
1162 sch->opm &= ~mask;
1163 sch->lpm &= ~mask;
1164 if (cdev)
1165 cdev->private->path_gone_mask |= mask;
1166 io_subchannel_terminate_path(sch, mask);
1167 break;
1168 case CHP_VARY_ON:
1169 sch->opm |= mask;
1170 sch->lpm |= mask;
1171 if (cdev)
1172 cdev->private->path_new_mask |= mask;
1173 io_subchannel_verify(sch);
1174 break;
1175 case CHP_OFFLINE:
1176 if (cio_update_schib(sch))
1177 return -ENODEV;
1178 if (cdev)
1179 cdev->private->path_gone_mask |= mask;
1180 io_subchannel_terminate_path(sch, mask);
1181 break;
1182 case CHP_ONLINE:
1183 if (cio_update_schib(sch))
1184 return -ENODEV;
1185 sch->lpm |= mask & sch->opm;
1186 if (cdev)
1187 cdev->private->path_new_mask |= mask;
1188 io_subchannel_verify(sch);
1189 break;
1190 case CHP_FCES_EVENT:
1191 /* Forward Endpoint Security event */
1192 for (chpid = 0, valid_bit = 0x80; chpid < 8; chpid++,
1193 valid_bit >>= 1) {
1194 if (mask & valid_bit)
1195 path_event[chpid] = PE_PATH_FCES_EVENT;
1196 else
1197 path_event[chpid] = PE_NONE;
1198 }
1199 if (cdev && cdev->drv && cdev->drv->path_event)
1200 cdev->drv->path_event(cdev, path_event);
1201 break;
1202 }
1203 return 0;
1204 }
1205
io_subchannel_quiesce(struct subchannel * sch)1206 static void io_subchannel_quiesce(struct subchannel *sch)
1207 {
1208 struct ccw_device *cdev;
1209 int ret;
1210
1211 spin_lock_irq(sch->lock);
1212 cdev = sch_get_cdev(sch);
1213 if (cio_is_console(sch->schid))
1214 goto out_unlock;
1215 if (!sch->schib.pmcw.ena)
1216 goto out_unlock;
1217 ret = cio_disable_subchannel(sch);
1218 if (ret != -EBUSY)
1219 goto out_unlock;
1220 if (cdev->handler)
1221 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1222 while (ret == -EBUSY) {
1223 cdev->private->state = DEV_STATE_QUIESCE;
1224 cdev->private->iretry = 255;
1225 ret = ccw_device_cancel_halt_clear(cdev);
1226 if (ret == -EBUSY) {
1227 ccw_device_set_timeout(cdev, HZ/10);
1228 spin_unlock_irq(sch->lock);
1229 wait_event(cdev->private->wait_q,
1230 cdev->private->state != DEV_STATE_QUIESCE);
1231 spin_lock_irq(sch->lock);
1232 }
1233 ret = cio_disable_subchannel(sch);
1234 }
1235 out_unlock:
1236 spin_unlock_irq(sch->lock);
1237 }
1238
io_subchannel_shutdown(struct subchannel * sch)1239 static void io_subchannel_shutdown(struct subchannel *sch)
1240 {
1241 io_subchannel_quiesce(sch);
1242 }
1243
device_is_disconnected(struct ccw_device * cdev)1244 static int device_is_disconnected(struct ccw_device *cdev)
1245 {
1246 if (!cdev)
1247 return 0;
1248 return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1249 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1250 }
1251
recovery_check(struct device * dev,void * data)1252 static int recovery_check(struct device *dev, void *data)
1253 {
1254 struct ccw_device *cdev = to_ccwdev(dev);
1255 struct subchannel *sch;
1256 int *redo = data;
1257
1258 spin_lock_irq(cdev->ccwlock);
1259 switch (cdev->private->state) {
1260 case DEV_STATE_ONLINE:
1261 sch = to_subchannel(cdev->dev.parent);
1262 if ((sch->schib.pmcw.pam & sch->opm) == sch->vpm)
1263 break;
1264 fallthrough;
1265 case DEV_STATE_DISCONNECTED:
1266 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1267 cdev->private->dev_id.ssid,
1268 cdev->private->dev_id.devno);
1269 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1270 *redo = 1;
1271 break;
1272 case DEV_STATE_DISCONNECTED_SENSE_ID:
1273 *redo = 1;
1274 break;
1275 }
1276 spin_unlock_irq(cdev->ccwlock);
1277
1278 return 0;
1279 }
1280
recovery_work_func(struct work_struct * unused)1281 static void recovery_work_func(struct work_struct *unused)
1282 {
1283 int redo = 0;
1284
1285 bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1286 if (redo) {
1287 spin_lock_irq(&recovery_lock);
1288 if (!timer_pending(&recovery_timer)) {
1289 if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1290 recovery_phase++;
1291 mod_timer(&recovery_timer, jiffies +
1292 recovery_delay[recovery_phase] * HZ);
1293 }
1294 spin_unlock_irq(&recovery_lock);
1295 } else
1296 CIO_MSG_EVENT(3, "recovery: end\n");
1297 }
1298
1299 static DECLARE_WORK(recovery_work, recovery_work_func);
1300
recovery_func(struct timer_list * unused)1301 static void recovery_func(struct timer_list *unused)
1302 {
1303 /*
1304 * We can't do our recovery in softirq context and it's not
1305 * performance critical, so we schedule it.
1306 */
1307 schedule_work(&recovery_work);
1308 }
1309
ccw_device_schedule_recovery(void)1310 void ccw_device_schedule_recovery(void)
1311 {
1312 unsigned long flags;
1313
1314 CIO_MSG_EVENT(3, "recovery: schedule\n");
1315 spin_lock_irqsave(&recovery_lock, flags);
1316 if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1317 recovery_phase = 0;
1318 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1319 }
1320 spin_unlock_irqrestore(&recovery_lock, flags);
1321 }
1322
purge_fn(struct device * dev,void * data)1323 static int purge_fn(struct device *dev, void *data)
1324 {
1325 struct ccw_device *cdev = to_ccwdev(dev);
1326 struct ccw_dev_id *id = &cdev->private->dev_id;
1327
1328 spin_lock_irq(cdev->ccwlock);
1329 if (is_blacklisted(id->ssid, id->devno) &&
1330 (cdev->private->state == DEV_STATE_OFFLINE) &&
1331 (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1332 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1333 id->devno);
1334 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1335 atomic_set(&cdev->private->onoff, 0);
1336 }
1337 spin_unlock_irq(cdev->ccwlock);
1338 /* Abort loop in case of pending signal. */
1339 if (signal_pending(current))
1340 return -EINTR;
1341
1342 return 0;
1343 }
1344
1345 /**
1346 * ccw_purge_blacklisted - purge unused, blacklisted devices
1347 *
1348 * Unregister all ccw devices that are offline and on the blacklist.
1349 */
ccw_purge_blacklisted(void)1350 int ccw_purge_blacklisted(void)
1351 {
1352 CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1353 bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1354 return 0;
1355 }
1356
ccw_device_set_disconnected(struct ccw_device * cdev)1357 void ccw_device_set_disconnected(struct ccw_device *cdev)
1358 {
1359 if (!cdev)
1360 return;
1361 ccw_device_set_timeout(cdev, 0);
1362 cdev->private->flags.fake_irb = 0;
1363 cdev->private->state = DEV_STATE_DISCONNECTED;
1364 if (cdev->online)
1365 ccw_device_schedule_recovery();
1366 }
1367
ccw_device_set_notoper(struct ccw_device * cdev)1368 void ccw_device_set_notoper(struct ccw_device *cdev)
1369 {
1370 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1371
1372 CIO_TRACE_EVENT(2, "notoper");
1373 CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1374 ccw_device_set_timeout(cdev, 0);
1375 cio_disable_subchannel(sch);
1376 cdev->private->state = DEV_STATE_NOT_OPER;
1377 }
1378
1379 enum io_sch_action {
1380 IO_SCH_UNREG,
1381 IO_SCH_ORPH_UNREG,
1382 IO_SCH_UNREG_CDEV,
1383 IO_SCH_ATTACH,
1384 IO_SCH_UNREG_ATTACH,
1385 IO_SCH_ORPH_ATTACH,
1386 IO_SCH_REPROBE,
1387 IO_SCH_VERIFY,
1388 IO_SCH_DISC,
1389 IO_SCH_NOP,
1390 };
1391
sch_get_action(struct subchannel * sch)1392 static enum io_sch_action sch_get_action(struct subchannel *sch)
1393 {
1394 struct ccw_device *cdev;
1395
1396 cdev = sch_get_cdev(sch);
1397 if (cio_update_schib(sch)) {
1398 /* Not operational. */
1399 if (!cdev)
1400 return IO_SCH_UNREG;
1401 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1402 return IO_SCH_UNREG;
1403 return IO_SCH_ORPH_UNREG;
1404 }
1405 /* Operational. */
1406 if (!cdev)
1407 return IO_SCH_ATTACH;
1408 if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1409 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1410 return IO_SCH_UNREG_ATTACH;
1411 return IO_SCH_ORPH_ATTACH;
1412 }
1413 if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1414 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1415 return IO_SCH_UNREG_CDEV;
1416 return IO_SCH_DISC;
1417 }
1418 if (device_is_disconnected(cdev))
1419 return IO_SCH_REPROBE;
1420 if (cdev->online)
1421 return IO_SCH_VERIFY;
1422 if (cdev->private->state == DEV_STATE_NOT_OPER)
1423 return IO_SCH_UNREG_ATTACH;
1424 return IO_SCH_NOP;
1425 }
1426
1427 /**
1428 * io_subchannel_sch_event - process subchannel event
1429 * @sch: subchannel
1430 * @process: non-zero if function is called in process context
1431 *
1432 * An unspecified event occurred for this subchannel. Adjust data according
1433 * to the current operational state of the subchannel and device. Return
1434 * zero when the event has been handled sufficiently or -EAGAIN when this
1435 * function should be called again in process context.
1436 */
io_subchannel_sch_event(struct subchannel * sch,int process)1437 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1438 {
1439 unsigned long flags;
1440 struct ccw_device *cdev;
1441 struct ccw_dev_id dev_id;
1442 enum io_sch_action action;
1443 int rc = -EAGAIN;
1444
1445 spin_lock_irqsave(sch->lock, flags);
1446 if (!device_is_registered(&sch->dev))
1447 goto out_unlock;
1448 if (work_pending(&sch->todo_work))
1449 goto out_unlock;
1450 cdev = sch_get_cdev(sch);
1451 if (cdev && work_pending(&cdev->private->todo_work))
1452 goto out_unlock;
1453 action = sch_get_action(sch);
1454 CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1455 sch->schid.ssid, sch->schid.sch_no, process,
1456 action);
1457 /* Perform immediate actions while holding the lock. */
1458 switch (action) {
1459 case IO_SCH_REPROBE:
1460 /* Trigger device recognition. */
1461 ccw_device_trigger_reprobe(cdev);
1462 rc = 0;
1463 goto out_unlock;
1464 case IO_SCH_VERIFY:
1465 /* Trigger path verification. */
1466 io_subchannel_verify(sch);
1467 rc = 0;
1468 goto out_unlock;
1469 case IO_SCH_DISC:
1470 ccw_device_set_disconnected(cdev);
1471 rc = 0;
1472 goto out_unlock;
1473 case IO_SCH_ORPH_UNREG:
1474 case IO_SCH_ORPH_ATTACH:
1475 ccw_device_set_disconnected(cdev);
1476 break;
1477 case IO_SCH_UNREG_CDEV:
1478 case IO_SCH_UNREG_ATTACH:
1479 case IO_SCH_UNREG:
1480 if (!cdev)
1481 break;
1482 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1483 /*
1484 * Note: delayed work triggered by this event
1485 * and repeated calls to sch_event are synchronized
1486 * by the above check for work_pending(cdev).
1487 */
1488 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1489 } else
1490 ccw_device_set_notoper(cdev);
1491 break;
1492 case IO_SCH_NOP:
1493 rc = 0;
1494 goto out_unlock;
1495 default:
1496 break;
1497 }
1498 spin_unlock_irqrestore(sch->lock, flags);
1499 /* All other actions require process context. */
1500 if (!process)
1501 goto out;
1502 /* Handle attached ccw device. */
1503 switch (action) {
1504 case IO_SCH_ORPH_UNREG:
1505 case IO_SCH_ORPH_ATTACH:
1506 /* Move ccw device to orphanage. */
1507 rc = ccw_device_move_to_orph(cdev);
1508 if (rc)
1509 goto out;
1510 break;
1511 case IO_SCH_UNREG_CDEV:
1512 case IO_SCH_UNREG_ATTACH:
1513 spin_lock_irqsave(sch->lock, flags);
1514 sch_set_cdev(sch, NULL);
1515 spin_unlock_irqrestore(sch->lock, flags);
1516 /* Unregister ccw device. */
1517 ccw_device_unregister(cdev);
1518 break;
1519 default:
1520 break;
1521 }
1522 /* Handle subchannel. */
1523 switch (action) {
1524 case IO_SCH_ORPH_UNREG:
1525 case IO_SCH_UNREG:
1526 css_sch_device_unregister(sch);
1527 break;
1528 case IO_SCH_ORPH_ATTACH:
1529 case IO_SCH_UNREG_ATTACH:
1530 case IO_SCH_ATTACH:
1531 dev_id.ssid = sch->schid.ssid;
1532 dev_id.devno = sch->schib.pmcw.dev;
1533 cdev = get_ccwdev_by_dev_id(&dev_id);
1534 if (!cdev) {
1535 sch_create_and_recog_new_device(sch);
1536 break;
1537 }
1538 rc = ccw_device_move_to_sch(cdev, sch);
1539 if (rc) {
1540 /* Release reference from get_ccwdev_by_dev_id() */
1541 put_device(&cdev->dev);
1542 goto out;
1543 }
1544 spin_lock_irqsave(sch->lock, flags);
1545 ccw_device_trigger_reprobe(cdev);
1546 spin_unlock_irqrestore(sch->lock, flags);
1547 /* Release reference from get_ccwdev_by_dev_id() */
1548 put_device(&cdev->dev);
1549 break;
1550 default:
1551 break;
1552 }
1553 return 0;
1554
1555 out_unlock:
1556 spin_unlock_irqrestore(sch->lock, flags);
1557 out:
1558 return rc;
1559 }
1560
ccw_device_set_int_class(struct ccw_device * cdev)1561 static void ccw_device_set_int_class(struct ccw_device *cdev)
1562 {
1563 struct ccw_driver *cdrv = cdev->drv;
1564
1565 /* Note: we interpret class 0 in this context as an uninitialized
1566 * field since it translates to a non-I/O interrupt class. */
1567 if (cdrv->int_class != 0)
1568 cdev->private->int_class = cdrv->int_class;
1569 else
1570 cdev->private->int_class = IRQIO_CIO;
1571 }
1572
1573 #ifdef CONFIG_CCW_CONSOLE
ccw_device_enable_console(struct ccw_device * cdev)1574 int __init ccw_device_enable_console(struct ccw_device *cdev)
1575 {
1576 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1577 int rc;
1578
1579 if (!cdev->drv || !cdev->handler)
1580 return -EINVAL;
1581
1582 io_subchannel_init_fields(sch);
1583 rc = cio_commit_config(sch);
1584 if (rc)
1585 return rc;
1586 sch->driver = &io_subchannel_driver;
1587 io_subchannel_recog(cdev, sch);
1588 /* Now wait for the async. recognition to come to an end. */
1589 spin_lock_irq(cdev->ccwlock);
1590 while (!dev_fsm_final_state(cdev))
1591 ccw_device_wait_idle(cdev);
1592
1593 /* Hold on to an extra reference while device is online. */
1594 get_device(&cdev->dev);
1595 rc = ccw_device_online(cdev);
1596 if (rc)
1597 goto out_unlock;
1598
1599 while (!dev_fsm_final_state(cdev))
1600 ccw_device_wait_idle(cdev);
1601
1602 if (cdev->private->state == DEV_STATE_ONLINE)
1603 cdev->online = 1;
1604 else
1605 rc = -EIO;
1606 out_unlock:
1607 spin_unlock_irq(cdev->ccwlock);
1608 if (rc) /* Give up online reference since onlining failed. */
1609 put_device(&cdev->dev);
1610 return rc;
1611 }
1612
ccw_device_create_console(struct ccw_driver * drv)1613 struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
1614 {
1615 struct io_subchannel_private *io_priv;
1616 struct ccw_device *cdev;
1617 struct subchannel *sch;
1618
1619 sch = cio_probe_console();
1620 if (IS_ERR(sch))
1621 return ERR_CAST(sch);
1622
1623 io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1624 if (!io_priv)
1625 goto err_priv;
1626 io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1627 sizeof(*io_priv->dma_area),
1628 &io_priv->dma_area_dma, GFP_KERNEL);
1629 if (!io_priv->dma_area)
1630 goto err_dma_area;
1631 set_io_private(sch, io_priv);
1632 cdev = io_subchannel_create_ccwdev(sch);
1633 if (IS_ERR(cdev)) {
1634 dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1635 io_priv->dma_area, io_priv->dma_area_dma);
1636 set_io_private(sch, NULL);
1637 put_device(&sch->dev);
1638 kfree(io_priv);
1639 return cdev;
1640 }
1641 cdev->drv = drv;
1642 ccw_device_set_int_class(cdev);
1643 return cdev;
1644
1645 err_dma_area:
1646 kfree(io_priv);
1647 err_priv:
1648 put_device(&sch->dev);
1649 return ERR_PTR(-ENOMEM);
1650 }
1651
ccw_device_destroy_console(struct ccw_device * cdev)1652 void __init ccw_device_destroy_console(struct ccw_device *cdev)
1653 {
1654 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1655 struct io_subchannel_private *io_priv = to_io_private(sch);
1656
1657 set_io_private(sch, NULL);
1658 dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1659 io_priv->dma_area, io_priv->dma_area_dma);
1660 put_device(&sch->dev);
1661 put_device(&cdev->dev);
1662 kfree(io_priv);
1663 }
1664
1665 /**
1666 * ccw_device_wait_idle() - busy wait for device to become idle
1667 * @cdev: ccw device
1668 *
1669 * Poll until activity control is zero, that is, no function or data
1670 * transfer is pending/active.
1671 * Called with device lock being held.
1672 */
ccw_device_wait_idle(struct ccw_device * cdev)1673 void ccw_device_wait_idle(struct ccw_device *cdev)
1674 {
1675 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1676
1677 while (1) {
1678 cio_tsch(sch);
1679 if (sch->schib.scsw.cmd.actl == 0)
1680 break;
1681 udelay(100);
1682 }
1683 }
1684 #endif
1685
1686 /**
1687 * get_ccwdev_by_busid() - obtain device from a bus id
1688 * @cdrv: driver the device is owned by
1689 * @bus_id: bus id of the device to be searched
1690 *
1691 * This function searches all devices owned by @cdrv for a device with a bus
1692 * id matching @bus_id.
1693 * Returns:
1694 * If a match is found, its reference count of the found device is increased
1695 * and it is returned; else %NULL is returned.
1696 */
get_ccwdev_by_busid(struct ccw_driver * cdrv,const char * bus_id)1697 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1698 const char *bus_id)
1699 {
1700 struct device *dev;
1701
1702 dev = driver_find_device_by_name(&cdrv->driver, bus_id);
1703
1704 return dev ? to_ccwdev(dev) : NULL;
1705 }
1706
1707 /************************** device driver handling ************************/
1708
1709 /* This is the implementation of the ccw_driver class. The probe, remove
1710 * and release methods are initially very similar to the device_driver
1711 * implementations, with the difference that they have ccw_device
1712 * arguments.
1713 *
1714 * A ccw driver also contains the information that is needed for
1715 * device matching.
1716 */
1717 static int
ccw_device_probe(struct device * dev)1718 ccw_device_probe (struct device *dev)
1719 {
1720 struct ccw_device *cdev = to_ccwdev(dev);
1721 struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1722 int ret;
1723
1724 cdev->drv = cdrv; /* to let the driver call _set_online */
1725 ccw_device_set_int_class(cdev);
1726 ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1727 if (ret) {
1728 cdev->drv = NULL;
1729 cdev->private->int_class = IRQIO_CIO;
1730 return ret;
1731 }
1732
1733 return 0;
1734 }
1735
ccw_device_remove(struct device * dev)1736 static void ccw_device_remove(struct device *dev)
1737 {
1738 struct ccw_device *cdev = to_ccwdev(dev);
1739 struct ccw_driver *cdrv = cdev->drv;
1740 struct subchannel *sch;
1741 int ret;
1742
1743 if (cdrv->remove)
1744 cdrv->remove(cdev);
1745
1746 spin_lock_irq(cdev->ccwlock);
1747 if (cdev->online) {
1748 cdev->online = 0;
1749 ret = ccw_device_offline(cdev);
1750 spin_unlock_irq(cdev->ccwlock);
1751 if (ret == 0)
1752 wait_event(cdev->private->wait_q,
1753 dev_fsm_final_state(cdev));
1754 else
1755 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1756 "device 0.%x.%04x\n",
1757 ret, cdev->private->dev_id.ssid,
1758 cdev->private->dev_id.devno);
1759 /* Give up reference obtained in ccw_device_set_online(). */
1760 put_device(&cdev->dev);
1761 spin_lock_irq(cdev->ccwlock);
1762 }
1763 ccw_device_set_timeout(cdev, 0);
1764 cdev->drv = NULL;
1765 cdev->private->int_class = IRQIO_CIO;
1766 sch = to_subchannel(cdev->dev.parent);
1767 spin_unlock_irq(cdev->ccwlock);
1768 io_subchannel_quiesce(sch);
1769 __disable_cmf(cdev);
1770 }
1771
ccw_device_shutdown(struct device * dev)1772 static void ccw_device_shutdown(struct device *dev)
1773 {
1774 struct ccw_device *cdev;
1775
1776 cdev = to_ccwdev(dev);
1777 if (cdev->drv && cdev->drv->shutdown)
1778 cdev->drv->shutdown(cdev);
1779 __disable_cmf(cdev);
1780 }
1781
1782 static struct bus_type ccw_bus_type = {
1783 .name = "ccw",
1784 .match = ccw_bus_match,
1785 .uevent = ccw_uevent,
1786 .probe = ccw_device_probe,
1787 .remove = ccw_device_remove,
1788 .shutdown = ccw_device_shutdown,
1789 };
1790
1791 /**
1792 * ccw_driver_register() - register a ccw driver
1793 * @cdriver: driver to be registered
1794 *
1795 * This function is mainly a wrapper around driver_register().
1796 * Returns:
1797 * %0 on success and a negative error value on failure.
1798 */
ccw_driver_register(struct ccw_driver * cdriver)1799 int ccw_driver_register(struct ccw_driver *cdriver)
1800 {
1801 struct device_driver *drv = &cdriver->driver;
1802
1803 drv->bus = &ccw_bus_type;
1804
1805 return driver_register(drv);
1806 }
1807
1808 /**
1809 * ccw_driver_unregister() - deregister a ccw driver
1810 * @cdriver: driver to be deregistered
1811 *
1812 * This function is mainly a wrapper around driver_unregister().
1813 */
ccw_driver_unregister(struct ccw_driver * cdriver)1814 void ccw_driver_unregister(struct ccw_driver *cdriver)
1815 {
1816 driver_unregister(&cdriver->driver);
1817 }
1818
ccw_device_todo(struct work_struct * work)1819 static void ccw_device_todo(struct work_struct *work)
1820 {
1821 struct ccw_device_private *priv;
1822 struct ccw_device *cdev;
1823 struct subchannel *sch;
1824 enum cdev_todo todo;
1825
1826 priv = container_of(work, struct ccw_device_private, todo_work);
1827 cdev = priv->cdev;
1828 sch = to_subchannel(cdev->dev.parent);
1829 /* Find out todo. */
1830 spin_lock_irq(cdev->ccwlock);
1831 todo = priv->todo;
1832 priv->todo = CDEV_TODO_NOTHING;
1833 CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
1834 priv->dev_id.ssid, priv->dev_id.devno, todo);
1835 spin_unlock_irq(cdev->ccwlock);
1836 /* Perform todo. */
1837 switch (todo) {
1838 case CDEV_TODO_ENABLE_CMF:
1839 cmf_reenable(cdev);
1840 break;
1841 case CDEV_TODO_REBIND:
1842 ccw_device_do_unbind_bind(cdev);
1843 break;
1844 case CDEV_TODO_REGISTER:
1845 io_subchannel_register(cdev);
1846 break;
1847 case CDEV_TODO_UNREG_EVAL:
1848 if (!sch_is_pseudo_sch(sch))
1849 css_schedule_eval(sch->schid);
1850 fallthrough;
1851 case CDEV_TODO_UNREG:
1852 spin_lock_irq(sch->lock);
1853 sch_set_cdev(sch, NULL);
1854 spin_unlock_irq(sch->lock);
1855 ccw_device_unregister(cdev);
1856 break;
1857 default:
1858 break;
1859 }
1860 /* Release workqueue ref. */
1861 put_device(&cdev->dev);
1862 }
1863
1864 /**
1865 * ccw_device_sched_todo - schedule ccw device operation
1866 * @cdev: ccw device
1867 * @todo: todo
1868 *
1869 * Schedule the operation identified by @todo to be performed on the slow path
1870 * workqueue. Do nothing if another operation with higher priority is already
1871 * scheduled. Needs to be called with ccwdev lock held.
1872 */
ccw_device_sched_todo(struct ccw_device * cdev,enum cdev_todo todo)1873 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
1874 {
1875 CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
1876 cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
1877 todo);
1878 if (cdev->private->todo >= todo)
1879 return;
1880 cdev->private->todo = todo;
1881 /* Get workqueue ref. */
1882 if (!get_device(&cdev->dev))
1883 return;
1884 if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
1885 /* Already queued, release workqueue ref. */
1886 put_device(&cdev->dev);
1887 }
1888 }
1889
1890 /**
1891 * ccw_device_siosl() - initiate logging
1892 * @cdev: ccw device
1893 *
1894 * This function is used to invoke model-dependent logging within the channel
1895 * subsystem.
1896 */
ccw_device_siosl(struct ccw_device * cdev)1897 int ccw_device_siosl(struct ccw_device *cdev)
1898 {
1899 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1900
1901 return chsc_siosl(sch->schid);
1902 }
1903 EXPORT_SYMBOL_GPL(ccw_device_siosl);
1904
1905 EXPORT_SYMBOL(ccw_device_set_online);
1906 EXPORT_SYMBOL(ccw_device_set_offline);
1907 EXPORT_SYMBOL(ccw_driver_register);
1908 EXPORT_SYMBOL(ccw_driver_unregister);
1909 EXPORT_SYMBOL(get_ccwdev_by_busid);
1910